21399730867 has 8 divisors (see below), whose sum is σ = 21538704096. Its totient is φ = 21260886912.

The previous prime is 21399730853. The next prime is 21399730901. The reversal of 21399730867 is 76803799312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21399730867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21399730567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 311643 + ... + 374059.

It is an arithmetic number, because the mean of its divisors is an integer number (2692338012).

Almost surely, 2^21399730867 is an apocalyptic number.

21399730867 is a deficient number, since it is larger than the sum of its proper divisors (138973229).

21399730867 is a wasteful number, since it uses less digits than its factorization.

21399730867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64637.

The product of its (nonzero) digits is 3429216, while the sum is 55.

The spelling of 21399730867 in words is "twenty-one billion, three hundred ninety-nine million, seven hundred thirty thousand, eight hundred sixty-seven".